Reconciling Model-Observation Reconciliations

Two very different representations of consistency between models and observations are popularly circulated. On the one hand, John Christy and Roy Spencer have frequently shown a graphic which purports to show a marked discrepancy between models and observations in tropical mid-troposphere, while, on the other hand, Zeke Hausfather, among others, have shown graphics which purport to show no discrepancy whatever between models and observations. I’ve commented on this topic on a number of occasions over the years, including two posts discussing AR5 graphics (here, here) with an update comparison in 2016 (here) and in 2017 (tweet).

There are several moving parts in such comparisons: troposphere or surface, tropical or global. Choice of reference period affects the rhetorical impression of time series plots. Boxplot comparisons of trends avoids this problem. I’ve presented such boxplots in the past and update for today’s post.